Thought I'd provide another update as it may be useful to others.

The last round of needed repairs netted a grand total of two weeks and 300 miles of worry free operation then left me stranded with another sudden and unexpected shutdown while driving. @#$%& is what I said and hauled it back home on a dolly. Few days have passed before I even bother to investigate this latest offering to the diagnostic gods.

Start at the beginning: Spark at coil - yep, Spark at plugs - yep, Fuel pressure - yep, WTH? OK Honey, fire it up! And it does easily and smoothly. WTH?
So I'm beginning to think perhaps a loose connection at the computer, fuse box or who knows where despite having check all this before.
I go about wiggling, twisting, pulling and shaking every connector and wiring bundle I can get to. Last in that process was the weather pack connector to the coil and hey, it shutdown.
Hey honey, fire it back up! and it does. Repeated manipulation of that weather pack showed an intermittent open on the positive lead. You mean to tell me that for three years and two owners this darn failing wire has eluded detection by a GM service garage, several other mechanics and me? Quite possibly! At Least I'm fairly confident that the gremlin has finally been located and dehydrated.

Bottom line is, and I've heard / read this repeatedly. Check all your wiring in these older vehicles because a fault can be well hidden in those dried up and brittle bundles.

PS … I still have a slow leak down on fuel pressure that will need addressed at some point.
Next on the hitlist will be brakes and shocks all around.
OH, and yesterday it let me know it wanted a new serpentine belt. Lol

 

I chased a check engine light for years, pointing towards a fault sensor on top of the fuel tank (tests the pressure/vacuum in the fuel tank). Swapped the sensor out 3 or 4 times, no luck. Finally I decided to check the wiring on the plug of that sensor, sure enough the actual copper wire inside the wire's coating for one of the 3 wires going to the sensor's plug was broken, leading to no connection... Literally a 5 minute fix, and it's been trouble free ever since.

So yes, I would certainly second that, check your wire connections! Sometimes it's the simple things that can be the hardest track down...